SANDHOPPER. An amphipod crustacean. These so abound on sandy shores that often the whole surface of the sand seems to be alive with the multitudes which, leaping up for a few inches into the air, fill it like a swarm of dancing flies. They may also be found by digging in the sand, in which they burrow. Sandhoppers leap by bending the body together and throwing it open with a sudden jerk. They feed on almost any vegetable or animal substance, particularly on what is already dead and beginning to decay. They are themselves the food of crabs, and of many kinds of birds. See Amphipoda.